Back of Beyond (2012)

In Back of Beyond, Cody Hoyt, although a brilliant cop, is an alcoholic struggling with two months of sobriety when his friend Hank Winters turns up dead in a remote mountain cabin. At first it looks like the suicide of a man who's fallen off the wagon, but Cody knows Hank better than that. As Cody digs deeper into the case, all roads lead to foul play. After years of bad behavior with his department, Cody in no position to be investigating a homicide. But he will stop at nothing to find out who murdered Hank. And why…

When clues found at the scene link the murderer to an outfitter leading tourists on a multiday wilderness horseback trip in Yellowstone National Park, Cody is desperate to get on the trail and stop the killer in his tracks. There's only one catch: his own son, Justin, is among the tourists. Now, in one of the most remote places on earth, Cody must enter a deadly cat-and-mouse game with a ruthless enemy who seems to know his every move...and is hell-bent on destroying the only important thing in Cody's life he has left.